Siemens 7SR224 - Instantaneous Sensitive Earth Fault Protection (50 SEF); Figure 3.4-2 Logic Diagram: SEF Instantaneous Element

7SR224 Argus Description of Operation
3.4.2 Instantaneous Sensitive Earth Fault Protection (50SEF)
Four elements are provided e.g. giving the option of using two elements set to forward and two to reverse.
Each instantaneous element has independent settings for pick-up current 50SEF-n Setting and a follower time
delay 50SEF-n Delay. The instantaneous elements have transient free operation.
For the directional elements the direction of operation can be set using 50SEF-n Dir. Control setting. Directional
logic is provided independently for each 50SEF-n element.
Operation of the instantaneous earth fault elements can be inhibited from:
Inhibit 50SEF-n A binary or virtual input, or function key
79 SEF Inst Trips: 50SEF-n When ‘delayed’ trips only are allowed in the autoreclose sequence
(79 SEF Prot’n Trip n = Delayed).
50SEF-n VTSAction: Inhibit Operation of the VT Supervision function.
Figure 3.4-2 Logic Diagram: SEF Instantaneous Element
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